Cover opener for cases



Aug. 29, 1961 B. J. NIGRELLI ETAL 2,997,833

COVER OPENER FOR CASES Filed Dec. 18. 1959 4 Sheets-Sheet 2 A TTORNEY w EN Aug. 29, 1961 Filed Dec. 18, 1959 B. J. NIGRELLI ET AL COVER OPENER FOR CASES 4 Sheets-Sheet 3 (:72 INVENTORS "Ema/0 .1. IVIGRELL/ WE/VDELL E. STA/VDLEY I EDWARD M. SCHALLER JAMES W/TTMA/V/V 9, 1951 B. J. NIGRELLI ETAL 2,997,833

COVER OPENER FOR CASES 4 Sheets-Sheet 4 Filed Dec.

INVENTORS B/AG/O J. IVIGRELL/ WENDELL E. .STANDLEY EDWARD M. SGHALLER JA MES I. W/TTMA lwv B) Q W A TTORNE) United States The present invention relates to case cover opening machines and more particularly to the opening of hinged covers of paperboard containers in which the covers or closures are reinforced with flanges which usually cause the covers to be held relatively firmly in place so that they offer some resistance to being swung open.

A principal object of the invention is to provide a machine for opening hinged case covers while the cases are being advanced continuously to a loading point or other treating station.

Another object of the invention is to provide a machine of relatively simple design with a minimum number of operating parts, having control means to operate the cover opening members automatically as cases reach a selected point in their travel.

A further object of the invention is to provide cover opening mechanism including vacuum cups supported on frame elements which are arranged to move a limited distance with the cases and during such movement are adapted to swingably lift the case covers sufficiently to permit plow means to complete the operation.

A still further object of the invention is to provide a vacuum cup device arranged on an arm member hinged to a downwardly movable support, whereby such movement of the support will first bring the vacuum cups into grasping contact with the case cover and further downward movement of the support causes the arm to contact the cover hinge and utilize this supporting edge to change the movement of the vacuum cup arm to an upward swinging movement, thereby swinging the cover upward.

Additional and more specific objects and advantages of the present invention will become apparent as the descrip tion proceeds.

In the drawings, illustrating a preferred embodiment of the invention FIG. 1 is a side elevational view showing the manner of conveying cases past the cover opening mechanism;

FIG. 2 is a cross-sectional view taken along lines 22 of FIG. 1, looking in the direction of the arrows, showing the vacuum cup supports and operating means therefor;

FIG. 3 is a fragmentary detail sectional view taken along lines 33 of FIG. 2;

FIG. 4 is a fragmentary perspective view on an enlarged scale showing the details of the mounting of the vacuum cup mechanism on its movable support;

FIGS. 5, 6 and 7 are fragmentary detail views showing the vacuum cup mechanism in sequential positions relative to the cases and their covers; and

FIG. 8 is a schematic view in perspective showing control valves and wiring diagram for automatic operation of the cover opening mechanism.

In the embodiment of the invention herein disclosed paperboard cases with covers in closed position are moved on a conveyor past the cover opening mechanism. The cases to be operated upon may be of various specific styles such as cases with covers having flanges on three sides or with a single flange at the free edges of the covers as illustrated. The conveyor frame has thereon an upstanding frame section including guides for the vacuum cup cover lifting machinsm; A primary supporting member is movable bodily along the guides on each side of the path of the cases. The vacuum cups are mounted atent on swingable frames or arms pivoted on the primary supporting member. As the case comes into position the primary supporting member is moved down to bring the vacuum cups in engagement with the surfaces of the covers. The primary supporting member continues moving downward for a limited distance. This brings the mid-portions of the swingable arms against the hinges of the respective covers, causing the arms to pivot on the cover hinges. Provision is made to permit the vacuum cups to move forward with the cases for a short distance. Thus, the covers are partially swung open as the case advances. After the case has advanced a short distance and its covers have been partially swung up, the covers move into a position to be supported and further lifted by plow elements supported on the upstanding frame. The vacuum cups are then released from the covers by cutting off the vacuum and the primary supporting member is moved upward. The cups after being released are retracted by springs and the pivoted arms will be moved down to horizontal position as the primary supporting member is raised to its original position. The mechanism is then ready to treat the next succeeding case.

Referring more particularly to the drawings, the operating parts are preferably mounted on a frame 10 having vertical members 11, transverse members 12, 12 and longitudinal members 13, 13. A conveyor, indicated as a whole at 14, is supported on the frame to convey cases 15, 15 past the vacuum cup lifting mechanisms, indicated as a whole at 16, 16, which are of identical but reverse construction. Beyond the vacuum cup mechanism is arranged a plow member, indicated as a whole at 17, comprising a pair of flaring rod portions 18, 18.

The cases, as herein shown, have two hinged covers 20, 20 with flanges 21, 21 which may be in relatively close contact with each other when the case is closed. In numerous cases of this type of construction the cover flanges are so formed as to come into snug frictional contact and this tends to keep the covers firmly closed. The use of flanges on the covers however is not essential as it is entirely feasible to operate on case covers having no flanges. In practice, dividing elements or other internal construction is employed within the cases, whereby the covers, when closed, will be held approximately flush with the upper edges of the end walls 22, 22. As shovvn, the covers 20, 20 are hinged to the side walls 23, 23 along the usual crease or score lines 24, 24.

The conveyor 14 may be of any convenient construction. In the present instance angle bars 26, 26 are employed extending longitudinally of the frame 10. Transverse pieces 27 are secured to the angle bars and on these pieces are secured longitudinally extending flat bars 28, 28 which support the cases as they are conveyed. Guide bars 29, 29 may be employed to confine the cases within the desired path. These guides are secured on the ends of threaded studs 30, 30 suitably secured for in-and-out adjustment on side bars 31, 31, carried by the vertical webs of the angle bars 26. This construction also allows for adjustment of the conveyor to accommodate cases of varying widths. Q

In order to propel cases along the supporting bars a pair of sprocket chains 32, 32 is employed. These chains pass over the rear and front sprockets 33 and 34, journalled on shafts 35 and 36 respectively, carried in bearings on the longitudinal angle bars 26. Pusher rods 38, 33 have their ends secured in links of the sprocket chains. The links of the chains are slidably supported on the upper edges of the side bars 31. The pusher rods are spaced apart a distance somewhat in excess of the greatest length of cases to be handled. Cases to be treated may be delivered to the conveyor either by hand or by arranging the end of the conveyor 14 in operative relation to a feeding conveyor.

The conveyor chains are driven from a motor 39 through a reduction gear box 40 which includes a shaft on which a sprocket 41 is mounted, having a chain 42 passing thereover which passes at its other end over a sprocket 43 fixed on the shaft 36. As illustrated, the cases are delivered to the conveyor with their cover hinges extending parallel to the path of travel of the cases.

The vacuum cup cover lifting mechanism is preferably supported on a primary upstanding frame having spaced pairs of vertical members 46, 46, secured to the sides of a transverse channel member 45. The lower ends of the vertical members 46 are welded or otherwise suitably secured to the longitudinal base frame members 13, 13. Suspended from the channel members 45 are adjustable frame members 44, 44. These members have a horizontal web portion 44a in contact with the horizontal web 45a of the channel frame member 45. By forming a slot 45b in the horizontal web of the channel member and passing a bolt 45c through an opening in web 44a and through the slot in web 45a, each vertical frame member 44 may be secured in various positions with respect to the center line of the machine to accommodate cases of varying widths.

The primary support for each of the vacuum cup mechanisms comprises a block 48, one on each side of the conveyor, and slidable between vertically extending gibs 47, 47, mounted on members 44, 44. As the cover raising mechanisms at each side of the conveyor are identical, but reverse, further detail description will be limited to one of the units. The vacuum cups 49, 49 are carried by a secondary support which includes a vertically swingable arm 50 and an apertured boss or bracket 51 thereon through which is slidably secured a hollow rod or tube 52 to permit the cups to move parallel with the conveying path.

For the purpose of moving the primary support block 48 vertically, it is secured to a piston rod 53 operating within a cylinder 54 supported in depending position on the frame member 44. An extended tongue on the cylinder has an opening for a pin 56, the ends of which are held in extended prongs of a bracket 57. Each bracket 57 may be bolted or otherwise secured at selected vertical positions on its supporting frame member 44 to accommodate cases of varying heights. In the inactive position of the cover lifting mechanism the piston rod will be retracted fully with the piston 58 in raised position. Notches 4811 (see FIG. 4) are formed in the sides of the block 48 to receive the gibs 47 and guide the block in its vertical movement.

The ports of the cylinder are connected through conduits 59 and 60 and solenoid valve 61 to a source of compressed air. The valve 61 may be of conventional form and is preferably of the type described as a double solenoid operated, air piloted, four-way valve. For simplicity only the essential parts of the valve structure are illustrated. See FIG. 8. The means for controlling the valve 61 will be described below.

The arm 50 is mounted on the primary support block 48 with provision for swinging vertically when the block 48 is lowered. For this purpose side plates 64, 64 are secured to the block to extend below its lower edges. The arm 50 has a hinge pin 65. passing therethrough with the ends of the pin received in openings formed in the plates 64. When the piston 53 is in retracted position the arm 50 is held from upward movement by a rigid stop finger 66 secured on the lower end of the cylinder. The principal purpose of this finger is to move the arm back to horizontal position after it has been raised with respect to the primary support as explained below.

When the arm 50 is in an upwardly swung position it is preferably locked in such position. For this purpose a coil spring 67 is secured at one end on a pin 68 fixed in the plate 64 and at its other end on a pin 69 fixed in a downwardly projecting lug 70 on the arm 50. By comparison of FIGS. and 7 it is seen that, when the arm 50 is in horizontal position, the center line of the spring 67 is on the right side of the center of the hinge pin 65 as viewed in FIG. 5, and when the arm 50 has been swung up, the center line of the spring moves to the left and remains on the left side of the pin. See FIG. 7. By selecting a sufficiently strong spring it is apparent that the arm will be held releasably by the spring in raised position. The arm is held in its horizontal position and prevented from swinging downward by the fact that the right hand end of the arm moves into contact with the bottom surface of the block 48. See FIGS. 5 and 6.

As best shown in FIGS. 5, 6 and 7, the case cover may be swung upward by moving the primary support downward by the piston mechanism and at the same time activating the vacuum. cups to grip the surface of the cover. As the arm moves down from the position of FIG. 5 to that of FIG. 6, it remains level and the cups come to rest on the cover with the arm extending Hat on the cover and its hinge. Further downward movement of the primary support block after the cups have gripped the cover causes the arm 50 to rock around the cover hinge as on a fulcrum and swing the cover upward.

As the cover is being swung upward as shown in FIGS. 5, 6 and 7, and the case continues advancing along the conveyor, the mounting of the vacuum cups permits them to move forward with the case. As seen in FIG. 4, showing the right hand unit as viewed in FIG. 2, the cups after engaging the cover may move relatively to the arm 50 due to the mounting of the tube 52 in the boss 51. Means are provided which hold the tube 52 in a rearward position. This comprises abar 72 secured on-boss 51 and having an elongated slot 73 formed in its forward end; that is, the end toward which the conveyor travels. A stud 74 is threaded into a collar 75 which surrounds tube 52 and is held in place by a set screw 76. The upper end of the stud extends through the slot in bar 72 and acts as a guide to hold the lip portions of the vacuum cups in proper position to engage the cover. A coil spring 77 has one end secured to stud 74 and its other end secured to an upwardly extending portion 78 on the rear end of bar 72. This spring tends to retain the cups normally in a rearward position and allows the cups to advance when engaged with the cover of a case. Upon release of the cups from the cover the spring returns them to retracted position.

Each set of vacuum cups is connected to a source of negative pressure through a conduit 79 connected near one end of the tube 52. Control of the vacuum is effected by a valve 80 of generally conventional form, preferably a single solenoid operated, spring returned, air piloted, three-way valve. See FIG. 8. For simplicity only the essential parts of the valve structure are illustrated.

After the covers have been partially raised by the cups and before the vacuum on the cups is released, the cases will be advanced sufiiciently to reach the plow unit 17 which acts to continue the opening of the covers. As shown in FIGS. 1, 3 and 8, the flaring rods 18, 18 are preferably secured to the edges of a piece of relatively thin, rigid sheet material 82 into which the lower ends of spaced, threaded rods 83, 83 and 84 are secured. These rods are disposed in a triangular arrangement and have their upper portions passing through openings in supporting bars '85 and 86 secured to a cantilever frame member 87 joined at 88 to one of the upstanding frame portions 46. An adjustable strut 89, secured to the upstanding frame at 90, has its forward end connected to the forward end of frame member 87. The rods 83 and 84 may be raised or lowered and held in desired position by nuts threaded thereon and bearing on the upper and lower surfaces of the supporting bars 86 and 87. By suitably raising or lowering rods 83 and 84 the plow rods 18 may be placed in the desired position to complete the opening of the cases. The plow rods 18 converge rearwardly until they almost meet at which point they are brought straight back in a narrow U-shape 3 indicated at 91. After the partially raised covers are released by the vacuum cups the cases will have moved forward sufiiciently so that the covers may drop upon the plow portion 91 and be supported by this portion until the leading edges of the covers reach the flared plow portions 18.

Means are preferably employed to operate the cover opening means automatically, responsive to the travel of the cases past selected points along the conveyor. For this purpose trip switches are arranged in a suitable manner along the conveyor to be engaged by the cases in their travel. As best shown in FIG. 8, trip switches 92, 93 and 94 are placed along the conveyor with their actuating fingers 95, 96 and 97 extending into the path of the cases. The switch 92 is normally open and is adapted to be closed when the case moves against its trip finger, and such switch will remain closed until the case passes, whereupon the switch will return to open position. The switches 93 and 94 are norm-ally closed and will be opened by the case as it moves in contact with the trip fingers 96 and 97 and these switches will remain open until the case passes.

The switch 92 when closed by the moving case permits current to flow from the power lines through conductors a, b and c, then through normally closed switch 93 and conductors d and e through the coil of the solenoid valve 80 which controls the vacuum to the vacuum cups.

At the same time the solenoid valve 80 is actuated current will also flow through the coil of solenoid valve 61 through conductor a, through switch 92, conductors b and 1'', through the normally closed switch 94 and through conductors g and h. The valve will then be brought to the position in which compressed air is admitted above the pistons and the air below the pistons is released. The pistons we thus forced down to bring the arms 54] and the vacuum cups against the upper surfaces of the covers. The vacuum cups, being actuated, Will grip the covers and as the p' rimary support continues to move down below the level of the cover hinge the arms 50 will swing up around the hinges as pivot points and the covers will be partial-1y raised. The forward movement of the case will then bring the covers to the place where they can be engaged by the rear end 91 of the plow section.

While switch 92 is being kept closed by the case passing therealong the case will reach the trip finger 96 of switch 93 and by depressing this finger will cause the switch to open. Current will then be discontinued through the coil of solenoid valve 80 and the vacuum will be cut off from the cups allowing the covers to fall back upon the rear end 91 of the plow section. Further advancing movement of the case will cause it to engage and depress the trip finger 97 of switch 94, opening this switch and discontinuing the flow of current through the coil of solenoid valve 61. This will cause a reversal of the position of the valve parts and compressed air will flow into the cylinders below the piston, and the air above the pistons will be permitted to escape. The primary support blocks 48 will then be moved upward, carrying with them the arms 50 which for the first part of the movement will be inclined upward at an angle, held by the springs '67. This assures that the arms and the vacuum cups will be lifted promptly from the partially raised covers and will not tend to remain against the covers as they would in the absence of the use of the springs 67. As the supports reach their final raised position the arms 50 come into contact with the respective downwardly projecting stops 66 which cause the arms to swing down to a horizontal position, as shown in FIG. 2, in readiness to move down against the next case.

The passage of the trailing end of the case beyond the switches allows them to become reset for the next oncoming case. That is, switch 92 will move to its normally open position and switches 93 and 94 will move to their normally closed position. The spacing of the pusher rods 38, 38 on the conveyor is so related to the case length that a case moving over the trip switches will clear the last switch 94 before an oncoming case reaches the trip finger of switch 92. In practice the trip switches will be grouped more closely than indicated in the schematic view FIG. 8. In this view, for purposes of clarity of illustration, the spacing of the cases and the size of the switches is somewhat exaggerated.

As the case continues to move past the plow rods 18, 1-8 the covers will be swung to positions in which they will extend outward approximately in the plane of the upper edges of the side Walls. The cases are then ready to be received by another conveyor and carried past loading devices or other operating mechanisms as appropriate.

While in the description and drawings the case is conveniently represented as traveling in upright position on a conveyor and the vacuum cup supports are described as movable in a vertical direction to bring the cups into gripping relation to the case covers, it is obvious that the relationship of the mechanism, as herein disclosed, to the vertical is not vital. The principles of the invention can obviously be utilized with facility regardless of whether the cases are conveyed with their covers disposed upwardly or in other positions. It is therefore desired that the use of terminology relating the parts to vertical or horizontal positioning be considered as done in the interests of simplicity of definition and not in a limiting sense.

From the foregoing it is apparent that the present invention provides a cover opening mechanism for hinged cover cases that is completely automatic and is effective for opening the covers by positive action of the operating parts, requiring no slowing or stoppage of the case while the cover engaging parts are acting. Due to the arrangement by which the cover hinge lines are employed as pivots or fulcrum points for the cover raising arms, the machine may be employed to open the covers of cases of varying heights well over the height variation caused by manufacturing tolerances without special adjustment of the vacuum cup units.

While the present description sets forth a preferred embodiment of the invention, numerous changes may be made in the construction without departing from. the spirit of the invention, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

We claim:

1. In a cover opening mechanism for a rectangular, tour-wall, top-opening case having a cover hinged on the upper edge of a side Wall, the combination of a conveyor for advancing the case in a continuous movement along a path parallel to the cover hinge, a vacuum cup mechanism adjacent such path, said mechanism including a primary support member arranged for vertical movement, a secondary support including an arm disposed to extend over a case on the conveyor and pivoted at one end on the primary support member for free, upward swinging movement, a vacuumcup mounted for transverse movement on the free end portion of the arm, permitting the vacuum cup to move with a case on the conveyor, said arm being of a length to support the vacuum cup at a location adjacent a point intermediate the free edge of a cover and its hinge connection to a wall on a conveyed case, means for connecting the vacuum cup to a source of negative pressure, and means for lowering the primary support to bring an intermediate point of the upwardly swingable arm. into contact with the cover hinge to swing the cover to a partially raised position, and means engageable with the partially raised cover and independent of the vacuum 7 cup mechanism acting to raise the cover beyond such partially raised position.

2. In a cover opening mechanism for a rectangular, four-wall, top-opening case having a cover hinged on the upper edge of a side wall, the combination of a conveyor for advancing a case in a continuous movement along a path parallel to the cover hinge, a cover engaging mechanism adjacent such path, said mechanism including a vacuum cup, means for connecting the vacuum cup to a source of negative pressure, means for supporting the vacuum cup above the path of a case on the conveyor, means for moving the vacuum cup into contact with a case cover, and means for raising the cup upward and outward of the conveyor through an arcuate path extending transversely to the direction of movement of the conveyor after gripping engagement with the cover to swing the cover upward, said supporting means for the vacuum cup including means permitting limited forward movement of the vacuum cup with the cover as the case advances on the conveyor.

3. In a cover opening mechanism for a rectangular, four-wall, top-opening case having a cover hinged on the upper edge of a side wall, the combination of a conveyor for advancing a case in a continuous movement along a path parallel to the cover hinge, a cover engaging mechanism adjacent such path, said mechanism including a vacuum cup, means for connecting the vacuum cup to a source of negative pressure, means for supporting the vacuum cup above the path of a case on the conveyor, means for moving the vacuum cup into contact with a case cover, means for raising the cup upward and outward of the conveyor through an arcuate path after gripping engagement with the cover to swing the cover partially upward, said supporting means for the vacuum cup comprising a vertically extending guide element disposed outside the path of containers movable on the conveyor, a support member movable vertically on the guide element, an arm pivotally associated with the support member to swing in a vertical plane transverse to the direction of movement of the conveyor, guide means on said arm, a slidable element on which the vacuum cup is carried, such slidable element being movable in the guide means generally parallel to the direction of movement of the conveyor, and yielding means for urging the slidable element in a direction rearwardly of the direction of move ment of the conveyor, whereby the vacuumcup, after engagement with the hinged cover of a case moving on the conveyor, may move forward with the case cover a limited distance and after release of vacuum, the slidable element will be returned to its initial position.

4. In a cover opening mechanism for a rectangular, four-wall, top-opening case having a cover hinged on the upper edge of a side wall, the combination of a conveyor for advancing a case along a path parallel to the cover hinge, a cover engaging mechanism including a vacuum cup, means for connecting the vacuum cup to a source of negative pressure, primary support means for supporting the vacuum cup in spaced relation to the path of a case on the conveyor for bodily movement toward and from the conveyor, means responsive to the movement of a case on the conveyor for moving the primary support means downward past the upper edge of a case to bring the vacuum cup into contact with a case cover, the primary support means including means for swinging the vacuum cup upward and outward of the conveyor through a curved path to raise the cover as the primary support continues its downward movement, and means responsive to the further movement of the case for reversing the movement of the primary support means to lift the vacuum cup above the level of the case.

5. In a cover opening mechanism for a rectangular, four-wall, top-opening case having a cover hinged on the upper edge of a side wall, the combination of a conveyor for advancing the case in a continuous movement along a path parallel to the cover hinge, a vacuum cup mechanism adjacent such path, said mechanism including an upright frame, a support member movable vertically on the frame, an arm pivoted at its inner end on the support for free upward swinging movement and having its outer end extending beyond the path of the cover hinge of a case on the conveyor, a vacuum cup carried on the outer end portion of the arm and adapted to engage the surface of a cover between its hinge and free edge, means normally retaining the support in raised position to retain the pivoted arm and vacuum cup at a level above the top of the case, means for moving the support downward to a position in which the pivotal connection of the arm with the support is brought to a level below the cover hinge, whereby the arm will engage the cover hinge and cause its free end portion to swing upward, means responsive to the movement of the case along the conveyor to activate the means 'for moving the support downward and for connecting the vacuum cup to a source of negative pressure causing the vacuum cup to grip the cover, the means for carrying the vacuum cup on the pivoted arm including means for supporting the vacuum cup to move bodily with respect to the arm in the direction of the travel of the case on the conveyor, whereby the vacuum cup after its gripping engagement with the cover will swing the cover up and simultaneously move forward with the case, and means adapted to engage the under surface of the raised cover and continue its swinging movement as the case advances.

6. Mechanism as defined in claim 5, including means responsive tothe continued movement of the case for discontinuing the connection of the vacuum cup with the source of negative pressure and for returning the support to its raised position above the level of the top of the case.

7. In a cover opening mechanism for a rectangular, four-wall, top-opening case having a cover hinged on the upper edge of the side wall, the combination of a conveyor for advancing a case along a path parallel to the cover hinge, a support arranged for vertical movement, an arm mounted on the support to swing upwardly relative thereto, a vacuum cup carried on the arm in position to engage a case cover at a point spaced from its hinge, means for connecting the vacuum cup to a source of negative pressure to cause it to grip the cover, means for lowering the support below the level of the cover hinge to bring the vacuum cup against the case cover and to cause the free portion of the arm to engage and swing up about the cover hinge, whereby the upward swinging of the arm and vacuum cup will raise the cover.

References Cited in the file of this patent UNITED STATES PATENTS 

